Was the Attorney General leant on to change his mind?

Elizabeth Wilmshurst's resignation letter provides the first glimpse from inside Whitehall of the Attorney General's apparent change of heart over the legality of the war.

Elizabeth Wilmshurst's resignation letter provides the first glimpse from inside Whitehall of the Attorney General's apparent change of heart over the legality of the war.

Ms Wilmshurst disagreed fundamentally with the Attorney General that the invasion of Iraq would be legal under international law. Her resignation letter not only illustrates in stark terms the strength of her views, but, for the first time, highlights the Attorney General's change of opinion on the legality of invasion within the space of less than two weeks.

It could not come at a worse time for Tony Blair who has been trying to bury the issue before the general election. To many it will be seen as "the smoking gun", showing that the Attorney General did change his mind on the eve of war.

On 17 March, the Attorney General stated unequivocally that the use of force would be justified under international law. He set out his reasons in a one-page long parliamentary answer to MPs and peers

But only 10 days before, Lord Goldsmith produced a fuller document for Tony Blair in which he stopped short of giving a definitive view on whether war would be legal, and said it might be safer to secure a second UN resolution.

The Attorney General has always resolutely denied rumours he was leant on to change his mind. He has never discussed the process of how he came to the opinion he did but he has always insisted it was his "genuine and independent view."

What we do know is the Attorney General only ruled invasion would be legal after seeking an "unequivocal" statement from Tony Blair that Saddam Hussein had committed further breaches of UN resolutions. Mr Blair wrote to the Attorney General on 15 March saying it was his "unequivocal view that Iraq is in further material breach of its obligations."

Two days later Lord Goldsmith set out in a short parliamentary answer his case for the legality of the war.

In a further twist, only two weeks ago it emerged that, aside from his one-page reply to Parliament, there was no other formal advice from the Attorney General on the legality of war.

That admission, from the head of the home civil service Sir Andrew Turnbull, caused bafflement and bemusement. It prompted MPs to remark that Britain had invaded Iraq on the strength of a single piece of paper. Today's revelation demonstrates how divided the Government's own lawyers were on the issue.

The letter shows definitively that Elizabeth Wilmshurst was not the only Foreign Office lawyer to disagree that invading Iraq would be legal. Indeed she says that view was given "consistently" by her department.

Her views are shared by many international lawyers from around the world.

Ms Wilmshurst is now head of international law at the think tank Chatham House where she continues to look at Iraq, including the legality of the occupation.

She is careful with the words she uses and, since leaving Whitehall, she has been reticent about speaking publicly about the reasons for her resignation. Her letter demonstrates the battle she was having.